Chia Yen Wu celebrates with her caddie
after extending the match with a long birdie on the 26th hole (USGA)

Chia Yen Wu’s 30-hole battle with Lauren Stephenson wasn’t just the longest match yet this week, it was the longest 18-hole match in USGA history. Wu, the No. 63 seed, is just 13 years old and in the eighth grade, yet she was able to hold off Alabama’s Lauren Stephenson in an epic late-day battle.

It took an unprecedented 30 holes, but 13-year-old Chia Yen Wu is headed to the #USWomensAm semifinals. https://t.co/0nG7HgQ9ev

— USGA (@USGA) August 12, 2017

Both players had a lead of as much as 2 up during the early part of the match, but things really got interesting once they went into sudden death.

Perhaps the best turn of events came on Wu and Stephenson’s 26th hole. Stephenson stuffed an approach shot at the par 4, only to have Wu drain a 30-footer from the front of the green for her own birdie. Stephenson then found herself in a situation where she had to make her own short birdie putt just to extend the match, not win it.

From there, the pair traded pars for three more holes as they made USGA history (the previous record was 28 holes). Wu made a 20-footer for par on the 30th hole to eventually win the match. Wu, of Taiwan, had already proved herself as a marathon woman this week. She was part of an 11-for-8 playoff at the end of stroke play that bled into the first day of match play. Wu just keeps advancing through the bracket.

For her effort, Wu earns a shot at Sophia Schubert, a Texas senior. Schubert got past Mexico’s Isabella Fierro by stringing together a steady stream of pars on the front nine. Fierro had too many bogeys, and could never make up the ground on Schubert.

In the other semifinal match, two California college players remain (at the start of this tournament, there were 18 players with ties to seven different California college programs). Lilia Kha-Tu Vu of UCLA and Albane Valenzuela of Stanford will meet after hard-fought paths to this point in the championship.

You might say that Vu avenged Valenzuela’s Stanford teammate, stroke-play medalist Shannon Aubert in knocking off 14-year-old Lucy Li on Friday. Li fought off an epic comeback from Aubert in the Round of 16, but Li was too unsteady for Vu on Friday. In fact, Vu won the match handily – by a 4-and-3 margin – without ever making a birdie.

“I tried to play my best today,” she said. “My game wasn't really good today, so I was just trying to like hit it close and trying to make birdies, but I didn't make any.”

Vu is a player who, after knocking off a phenom five years her junior, referenced a high school slump that she overcame with help from her UCLA teammate Bronte Law. Ultimately, it was Vu’s confidence and experience that got her to the semifinals. UCLA head coach Carrie Forsyth called Vu a “match-play monster,” and it helped Vu to have her coach believe in her.

Vu’s best memory of Valenzuela, who she’ll meet in the semifinals on Saturday, is that the two once played three rounds together at a college golf tournament in San Luis Obispo, Calif., and Vu won.

Valenzuela remembers it, too, but here’s a player who can more than hold her own. The Stanford sophomore represented Switzerland in the Olympics a year ago. At the time, her younger brother was too young to caddie. So this week, as 15, Valenzuela made sure he got that chance.

Sights and sounds from a historic day @SdccClub, culminating in the longest match in USGA championship history. #USWomensAm 🎥 ⬇ pic.twitter.com/5AhHdeTvJW

— USGA (@USGA) August 12, 2017

Experiences like the Olympics, and her run to the finals of the European Ladies Amateur last month, set Valenzuela apart.

“When you play such big events, it helps you with pressure and just how to deal with that kind of events, that type of courses,” she said. “Just playing under very, very difficult conditions. Playing in majors before also helped me getting ready for the Olympics. But it just showed me that I have to stay very patient, very relaxed. I'm grateful to be in that kind of position still at 18, 19.”